/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "SdkConstants.h"
#include "flatten/ChunkWriter.h"
#include "flatten/ResourceTypeExtensions.h"
#include "flatten/XmlFlattener.h"
#include "xml/XmlDom.h"
#include <androidfw/ResourceTypes.h>
#include <algorithm>
#include <utils/misc.h>
#include <vector>
using namespace android;
namespace aapt {
namespace {
constexpr uint32_t kLowPriority = 0xffffffffu;
struct XmlFlattenerVisitor : public xml::Visitor {
using xml::Visitor::visit;
BigBuffer* mBuffer;
XmlFlattenerOptions mOptions;
StringPool mPool;
std::map<uint8_t, StringPool> mPackagePools;
struct StringFlattenDest {
StringPool::Ref ref;
ResStringPool_ref* dest;
};
std::vector<StringFlattenDest> mStringRefs;
// Scratch vector to filter attributes. We avoid allocations
// making this a member.
std::vector<xml::Attribute*> mFilteredAttrs;
XmlFlattenerVisitor(BigBuffer* buffer, XmlFlattenerOptions options) :
mBuffer(buffer), mOptions(options) {
}
void addString(const StringPiece16& str, uint32_t priority, android::ResStringPool_ref* dest) {
if (!str.empty()) {
mStringRefs.push_back(StringFlattenDest{
mPool.makeRef(str, StringPool::Context{ priority }),
dest });
} else {
// The device doesn't think a string of size 0 is the same as null.
dest->index = util::deviceToHost32(-1);
}
}
void addString(const StringPool::Ref& ref, android::ResStringPool_ref* dest) {
mStringRefs.push_back(StringFlattenDest{ ref, dest });
}
void writeNamespace(xml::Namespace* node, uint16_t type) {
ChunkWriter writer(mBuffer);
ResXMLTree_node* flatNode = writer.startChunk<ResXMLTree_node>(type);
flatNode->lineNumber = util::hostToDevice32(node->lineNumber);
flatNode->comment.index = util::hostToDevice32(-1);
ResXMLTree_namespaceExt* flatNs = writer.nextBlock<ResXMLTree_namespaceExt>();
addString(node->namespacePrefix, kLowPriority, &flatNs->prefix);
addString(node->namespaceUri, kLowPriority, &flatNs->uri);
writer.finish();
}
void visit(xml::Namespace* node) override {
writeNamespace(node, android::RES_XML_START_NAMESPACE_TYPE);
xml::Visitor::visit(node);
writeNamespace(node, android::RES_XML_END_NAMESPACE_TYPE);
}
void visit(xml::Text* node) override {
if (util::trimWhitespace(node->text).empty()) {
// Skip whitespace only text nodes.
return;
}
ChunkWriter writer(mBuffer);
ResXMLTree_node* flatNode = writer.startChunk<ResXMLTree_node>(RES_XML_CDATA_TYPE);
flatNode->lineNumber = util::hostToDevice32(node->lineNumber);
flatNode->comment.index = util::hostToDevice32(-1);
ResXMLTree_cdataExt* flatText = writer.nextBlock<ResXMLTree_cdataExt>();
addString(node->text, kLowPriority, &flatText->data);
writer.finish();
}
void visit(xml::Element* node) override {
{
ChunkWriter startWriter(mBuffer);
ResXMLTree_node* flatNode = startWriter.startChunk<ResXMLTree_node>(
RES_XML_START_ELEMENT_TYPE);
flatNode->lineNumber = util::hostToDevice32(node->lineNumber);
flatNode->comment.index = util::hostToDevice32(-1);
ResXMLTree_attrExt* flatElem = startWriter.nextBlock<ResXMLTree_attrExt>();
addString(node->namespaceUri, kLowPriority, &flatElem->ns);
addString(node->name, kLowPriority, &flatElem->name);
flatElem->attributeStart = util::hostToDevice16(sizeof(*flatElem));
flatElem->attributeSize = util::hostToDevice16(sizeof(ResXMLTree_attribute));
writeAttributes(node, flatElem, &startWriter);
startWriter.finish();
}
xml::Visitor::visit(node);
{
ChunkWriter endWriter(mBuffer);
ResXMLTree_node* flatEndNode = endWriter.startChunk<ResXMLTree_node>(
RES_XML_END_ELEMENT_TYPE);
flatEndNode->lineNumber = util::hostToDevice32(node->lineNumber);
flatEndNode->comment.index = util::hostToDevice32(-1);
ResXMLTree_endElementExt* flatEndElem = endWriter.nextBlock<ResXMLTree_endElementExt>();
addString(node->namespaceUri, kLowPriority, &flatEndElem->ns);
addString(node->name, kLowPriority, &flatEndElem->name);
endWriter.finish();
}
}
static bool cmpXmlAttributeById(const xml::Attribute* a, const xml::Attribute* b) {
if (a->compiledAttribute && a->compiledAttribute.value().id) {
if (b->compiledAttribute && b->compiledAttribute.value().id) {
return a->compiledAttribute.value().id.value() < b->compiledAttribute.value().id.value();
}
return true;
} else if (!b->compiledAttribute) {
int diff = a->namespaceUri.compare(b->namespaceUri);
if (diff < 0) {
return true;
} else if (diff > 0) {
return false;
}
return a->name < b->name;
}
return false;
}
void writeAttributes(xml::Element* node, ResXMLTree_attrExt* flatElem, ChunkWriter* writer) {
mFilteredAttrs.clear();
mFilteredAttrs.reserve(node->attributes.size());
// Filter the attributes.
for (xml::Attribute& attr : node->attributes) {
if (mOptions.maxSdkLevel && attr.compiledAttribute && attr.compiledAttribute.value().id) {
size_t sdkLevel = findAttributeSdkLevel(attr.compiledAttribute.value().id.value());
if (sdkLevel > mOptions.maxSdkLevel.value()) {
continue;
}
}
mFilteredAttrs.push_back(&attr);
}
if (mFilteredAttrs.empty()) {
return;
}
const ResourceId kIdAttr(0x010100d0);
std::sort(mFilteredAttrs.begin(), mFilteredAttrs.end(), cmpXmlAttributeById);
flatElem->attributeCount = util::hostToDevice16(mFilteredAttrs.size());
ResXMLTree_attribute* flatAttr = writer->nextBlock<ResXMLTree_attribute>(
mFilteredAttrs.size());
uint16_t attributeIndex = 1;
for (const xml::Attribute* xmlAttr : mFilteredAttrs) {
// Assign the indices for specific attributes.
if (xmlAttr->compiledAttribute && xmlAttr->compiledAttribute.value().id &&
xmlAttr->compiledAttribute.value().id.value() == kIdAttr) {
flatElem->idIndex = util::hostToDevice16(attributeIndex);
} else if (xmlAttr->namespaceUri.empty()) {
if (xmlAttr->name == u"class") {
flatElem->classIndex = util::hostToDevice16(attributeIndex);
} else if (xmlAttr->name == u"style") {
flatElem->styleIndex = util::hostToDevice16(attributeIndex);
}
}
attributeIndex++;
// Add the namespaceUri to the list of StringRefs to encode.
addString(xmlAttr->namespaceUri, kLowPriority, &flatAttr->ns);
flatAttr->rawValue.index = util::hostToDevice32(-1);
if (!xmlAttr->compiledAttribute || !xmlAttr->compiledAttribute.value().id) {
// The attribute has no associated ResourceID, so the string order doesn't matter.
addString(xmlAttr->name, kLowPriority, &flatAttr->name);
} else {
// Attribute names are stored without packages, but we use
// their StringPool index to lookup their resource IDs.
// This will cause collisions, so we can't dedupe
// attribute names from different packages. We use separate
// pools that we later combine.
//
// Lookup the StringPool for this package and make the reference there.
const xml::AaptAttribute& aaptAttr = xmlAttr->compiledAttribute.value();
StringPool::Ref nameRef = mPackagePools[aaptAttr.id.value().packageId()].makeRef(
xmlAttr->name, StringPool::Context{ aaptAttr.id.value().id });
// Add it to the list of strings to flatten.
addString(nameRef, &flatAttr->name);
}
if (mOptions.keepRawValues || !xmlAttr->compiledValue) {
// Keep raw values if the value is not compiled or
// if we're building a static library (need symbols).
addString(xmlAttr->value, kLowPriority, &flatAttr->rawValue);
}
if (xmlAttr->compiledValue) {
bool result = xmlAttr->compiledValue->flatten(&flatAttr->typedValue);
assert(result);
} else {
// Flatten as a regular string type.
flatAttr->typedValue.dataType = android::Res_value::TYPE_STRING;
addString(xmlAttr->value, kLowPriority,
(ResStringPool_ref*) &flatAttr->typedValue.data);
}
flatAttr->typedValue.size = util::hostToDevice16(sizeof(flatAttr->typedValue));
flatAttr++;
}
}
};
} // namespace
bool XmlFlattener::flatten(IAaptContext* context, xml::Node* node) {
BigBuffer nodeBuffer(1024);
XmlFlattenerVisitor visitor(&nodeBuffer, mOptions);
node->accept(&visitor);
// Merge the package pools into the main pool.
for (auto& packagePoolEntry : visitor.mPackagePools) {
visitor.mPool.merge(std::move(packagePoolEntry.second));
}
// Sort the string pool so that attribute resource IDs show up first.
visitor.mPool.sort([](const StringPool::Entry& a, const StringPool::Entry& b) -> bool {
return a.context.priority < b.context.priority;
});
// Now we flatten the string pool references into the correct places.
for (const auto& refEntry : visitor.mStringRefs) {
refEntry.dest->index = util::hostToDevice32(refEntry.ref.getIndex());
}
// Write the XML header.
ChunkWriter xmlHeaderWriter(mBuffer);
xmlHeaderWriter.startChunk<ResXMLTree_header>(RES_XML_TYPE);
// Flatten the StringPool.
StringPool::flattenUtf16(mBuffer, visitor.mPool);
{
// Write the array of resource IDs, indexed by StringPool order.
ChunkWriter resIdMapWriter(mBuffer);
resIdMapWriter.startChunk<ResChunk_header>(RES_XML_RESOURCE_MAP_TYPE);
for (const auto& str : visitor.mPool) {
ResourceId id = { str->context.priority };
if (id.id == kLowPriority || !id.isValid()) {
// When we see the first non-resource ID,
// we're done.
break;
}
*resIdMapWriter.nextBlock<uint32_t>() = id.id;
}
resIdMapWriter.finish();
}
// Move the nodeBuffer and append it to the out buffer.
mBuffer->appendBuffer(std::move(nodeBuffer));
// Finish the xml header.
xmlHeaderWriter.finish();
return true;
}
bool XmlFlattener::consume(IAaptContext* context, xml::XmlResource* resource) {
if (!resource->root) {
return false;
}
return flatten(context, resource->root.get());
}
} // namespace aapt